UV Index Monitor App that subscribes to PubNub and displays the UV index value. Code snippets for blog post. See project here: https://github.com/chandler767/PubNub-UV-Index-Monitor/

blankreactproject.js

import React, {Component} from 'react';
import {Platform, StyleSheet, Text, View} from 'react-native';

type Props = {};
export default class App extends Component<Props> {
  render() {
    return (
    );
  }
}

const styles = StyleSheet.create({
});

constructor.js

constructor(props) {
    super(props);
    this.state = {
         uvindex: 0,
         uvindexcolor: '#90EE90',
         hidewebview: false,
      }
    // Init PubNub. Use your subscribe key here.
    this.pubnub = new PubNubReact({
        subscribeKey: 'sub-key'
    });
    this.pubnub.init(this);
  }

functions.js

componentWillMount() {
  // Subscribe to uvindex channel and get messages.
  this.pubnub.subscribe({
      channels: ['uvindex']     
  });
  // Update when a new value is received.
  this.pubnub.getMessage('uvindex', (msg) => {
    this.UpdateUV(msg.message.eon.uvindex)
  });
  // Get and display last UV Index value.
  this.pubnub.history(
    {
        channel: 'uvindex',
        count: 1,
    },
    function (status, response) {
      if (status.statusCode == 200) {
        this.UpdateUV(response.messages[0].entry.eon.uvindex)
      }
    }.bind(this)
  );
}

componentWillUnmount() {
  // Unubscribe to uvindex channel.
  this.pubnub.unsubscribe({
      channels: ['uvindex']
  });
}

componentDidMount(){
  // Check the device orientation on load.
  this.DetectOrientation();
}

DetectOrientation(){
  // Hide and show webview.
  if(Dimensions.get('window').width > Dimensions.get('window').height) // Landscape - Show webview.
  {
    this.setState({
      hidewebview: true,
    });
  } else { // Portrait - Hide webview.
    this.setState({
      hidewebview: false,
    });
  }
}

// Update the UV Index label and set background color.
UpdateUV(uvindex){
  this.setState({uvindex: uvindex})
  if (uvindex < 3) { // Low 0-2
    this.setState({uvindexcolor: '#90EE90'}); // Green
  } else if ((uvindex >= 3) && (uvindex < 6)) { // Moderate 3-5
    this.setState({uvindexcolor: '#FFFF00'}); // Yellow
  } else if ((uvindex >= 6) && (uvindex < 8)) { // High 6-7
    this.setState({uvindexcolor: '#FFBE4D'}); // Orange
  } else if ((uvindex >= 8) && (uvindex < 11)) { // Very High 8-10
    this.setState({uvindexcolor: '#FF9999'}); // Red
  } else if (uvindex >= 11) { // Extreme 11+
    this.setState({uvindexcolor: '#FF99FF'}); // Purple
  };
}

gettoken.js

// Get token and subscribe for push notifications. 
RNFirebase.messaging().getToken().then(fcmToken => {
  if (fcmToken) {
    // console.log(fcmToken)
    this.pubnub.push.addChannels(
    {
        channels: ['uvindex'],
        device: fcmToken,
        pushGateway: 'gcm' // apns, gcm, mpns
    });
  } 
});

imports.js

import React, {Component} from 'react';
import {StyleSheet, Text, View, Dimensions, WebView} from 'react-native'
import PubNubReact from 'pubnub-react';

refreshedtoken.js

// Get refreshed token and subscribe for push notifications. 
this.onTokenRefreshListener = RNFirebase.messaging().onTokenRefresh(fcmToken => {
  // console.log(fcmToken)
  this.pubnub.push.addChannels(
  {
      channels: ['uvindex'],
      device: fcmToken,
      pushGateway: 'gcm' // apns, gcm, mpns
  });    
});

styles.js

container: {
  flex: 1,
  justifyContent: 'center',
  alignItems: 'center',
},
welcome: {
  fontSize: 45,
  margin: 10,
  paddingTop: 25,
  color: '#000000',
},
uvindex: {
  fontSize: 100,
  marginBottom: 15,
  fontWeight: 'bold',
  color: '#000000',
},
webcontainer: {
  top: 0,
  left: 0,
  bottom: 0,
  right: 0,
  position: 'absolute',
  alignItems: 'flex-start',
},
webview: {
  top: 0,
  left: 0,
  position: 'absolute',
  height: '100%',
  width: '100%',
},

views.js

//Display the UV Index
<View style={[styles.container, {backgroundColor: this.state.uvindexcolor}]} onLayout={(event) => this.DetectOrientation()}>
  <Text style={styles.welcome}>UV Index</Text>
  <Text style={styles.uvindex}>{this.state.uvindex}</Text>
  {
    this.state.hidewebview ? 
    <View style={styles.webcontainer}>
      <WebView
        style={styles.webview}
        source={{uri: 'https://uvindex.chandlermayo.com/'}}
        scalesPageToFit
        javaScriptEnabled
        domStorageEnabled
        startInLoadingState/>
    </View> : null
  }
</View>